HNO3 modified biochars for uranium (VI) removal from aqueous solution
HNO3 modified biochars for uranium (VI) removal from aqueous solution
复制标题
用于从水溶液中去除铀 (VI) 的 HNO3 改性生物炭
DOI：
10.1016/j.biortech.2018.02.022
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发表时间：
2018-05-01
影响因子：
11.4
通讯作者：
Wang, Xiangke
中科院分区：
文献类型：
--
作者：
Jin, Jie;Li, Shiwei;Wang, Xiangke
采用HNO 3对以小麦秸秆和牛粪为原料制备的生物炭进行化学改性，研究其对水中U（VI）的去除效果。宏观实验表明，U（VI）在生物炭上的富集受表面络合作用和静电相互作用的调控。FTIR和XPS分析证实了生物炭表面羧基的存在是其对U（VI）的高效吸附的主要原因。R-CH_2 OH基团的还原剂促进了U（VI）在未处理生物炭上的吸附。改性后的生物炭表面COO基团含量增加，表面负电荷增加，对U（VI）的吸附能力增强。在pH 4.5和298 K时，氧化后的WH对U（VI）的最大吸附量为355.6 mg/g，比未氧化的WH提高了40倍，高于大多数碳基吸附剂。
The HNO3 treatment was used to chemically modify the biochars produced from wheat straw (WH) and cow manure for U(VI) removal from aqueous solution. Macroscopic experiments proved that the enrichment of U(VI) on the biochars was regulated by surface complexation and electrostatic interactions. FTIR and XPS analyses confirmed that the highly efficient adsorption of U(VI) was due to the carboxyl groups on the biochar surfaces. The reducing agents of the R-CH2OH groups facilitated U(VI) adsorption on the untreated biochars. Owing to the higher contents of surface COO groups and more negative surface charge, the modified biochars showed enhanced U(VI) adsorption ability than the untreated ones. The maximum adsorption capacity of U(VI) by the oxidized WH was calculated to be 355.6 mg/g at pH 4.5 and 298 K, which was an improvement of 40 times relative to the untreated WH and was higher than that of most carbon-based adsorbents.